Initial Installation, or Upgrade?

You can choose to perform an initial installation or, if your system
is already running the Solaris OS, you can upgrade your system.

Initial Installation

An initial installation overwrites the system's disk with the new version
of the Solaris OS. If your system is not running the Solaris OS, you must
perform an initial installation.

If the system is already running the Solaris OS, you can choose to perform
an initial installation. If you want to preserve any local modifications,
before you install, you must back up the local modifications. After you complete
the installation, you can restore the local modifications.

You can use any of the Solaris installation methods to perform an initial
installation. For detailed information about the different Solaris installation
methods, refer to Choosing a Solaris Installation Method.

Upgrade

You can upgrade the Solaris OS by using two upgrade methods: standard
and Solaris Live Upgrade. A standard upgrade maintains as many existing configuration
parameters as possible of the current Solaris OS. Solaris Live Upgrade creates
a copy of the current system. This copy can be upgraded with a standard upgrade.
The upgraded Solaris OS can then be switched to become the current system
by a simple reboot. If a failure occurs, you can switch back to the original
Solaris OS with a reboot. Solaris Live Upgrade enables you to keep your system
running while you upgrade and enables you to switch back and forth between
Solaris OS releases.

For more information about upgrading and the list of upgrade methods,
see Upgrade Planning.